Paper 2005/085

A new structural attack for GPT and variants

R. Overbeck

Abstract

In this paper we look at the Gabidulin version of the McEliece cryptosystem (GPT) and its variants. We propose a new polynomial time attack on the private key, which is applicable to all variants proposed so far, breaking some of them completely.

Note: One of the assumptions we made in the previous version of this paper has turned out to be false. However, as is shown in the current version, it is not essential for the analysis. Thus the results remain unchanged.